Research is proposed to investigate cellular mechanisms which contribute to the regulation of aqueous humor dynamics. Adrenergic receptors in the cells governing the formation of aqueous humor by the ciliary processes and on the cells governing the outflow of aqueous tumor by the trabecular meshwork will be characterized using biochemical, receptor-radioligand binding assays. Hypotheses to explain pharmacological responsiveness will be explored in relationship to drug-induced changes and age-related changes in receptor populations. Evidence will be sought for a role for cyclic AMP-mediated pathways in regulating the flow of aqueous humor and the maintenance of intraocular pressure. To study specific cellular components of response pathways, cell culture of ciliary process epithelium, trabecular endothelium and vascular endothelium will be established.